Get your smoker to 250F. I personally used a Weber kettle with the Slow N' Sear, however what you use may vary; Your goal should be to maintain around 250F.
Once the grill has stabilized, place a post-oak wood chunk on the coals and allow it to smolder.
Bring the chuck roast outside and place in the cool zone of the smoker - opposite of your fire.
Check on the meat every hour. If you notice certain parts are finishing faster than the other, turn the meat accordingly, ie. position the end that needs more love towards the fire. Add a new post-oak wood chunk every hour you check the meat.
After roughly 3 hours, the chuck roast has likely taken on enough smoke. The outside has likely developed a bark and is ready to be wrapped in aluminum foil. Wrap the chuck roast tightly in two layers of aluminum foil.
Place the wrapped chuck roast back on the smoker in the cool zone.
Start checking internal temperature with a meat thermometer every hour. Chuck roast isn't a large piece of meat and will quickly blow past any sort of meat stall when wrapped in aluminum foil.
This process took two more hours to reach 198F. At this point the meat was probe tender. When checking for done-ness, use your meat thermometer to poke the meat - if it feels like it's sliding through hot butter, it's done. However, if it has resistance, it needs to continue smoking in the tinfoil.
